[PATCH 1/2] Split out solve_add_graph_edge

[Richard Biener via Gcc-patches]

Split out a worker with all the special-casings when adding a graph
edge during solving.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

        * tree-ssa-structalias.cc (solve_add_graph_edge): New function,
        split out from ...
        (do_sd_constraint): ... here.
---
 gcc/tree-ssa-structalias.cc | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/gcc/tree-ssa-structalias.cc b/gcc/tree-ssa-structalias.cc
index 39c342fae41..84c625d53e5 100644
--- a/gcc/tree-ssa-structalias.cc
+++ b/gcc/tree-ssa-structalias.cc
@@ -1640,6 +1640,29 @@ topo_visit (constraint_graph_t graph, struct topo_info 
*ti,
   ti->topo_order.safe_push (n);
 }
 
+/* Add a copy edge FROM -> TO, optimizing special cases.  Returns TRUE
+   if the solution of TO changed.  */
+
+static bool
+solve_add_graph_edge (constraint_graph_t graph, unsigned int to,
+                     unsigned int from)
+{
+  /* Adding edges from the special vars is pointless.
+     They don't have sets that can change.  */
+  if (get_varinfo (from)->is_special_var)
+    return bitmap_ior_into (get_varinfo (to)->solution,
+                           get_varinfo (from)->solution);
+  /* Merging the solution from ESCAPED needlessly increases
+     the set.  Use ESCAPED as representative instead.  */
+  else if (from == find (escaped_id))
+    return bitmap_set_bit (get_varinfo (to)->solution, escaped_id);
+  else if (get_varinfo (from)->may_have_pointers
+          && add_graph_edge (graph, to, from))
+    return bitmap_ior_into (get_varinfo (to)->solution,
+                           get_varinfo (from)->solution);
+  return false;
+}
+
 /* Process a constraint C that represents x = *(y + off), using DELTA as the
    starting solution for y.  */
 
@@ -1700,17 +1723,7 @@ do_sd_constraint (constraint_graph_t graph, constraint_t 
c,
        {
          t = find (v->id);
 
-         /* Adding edges from the special vars is pointless.
-            They don't have sets that can change.  */
-         if (get_varinfo (t)->is_special_var)
-           flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
-         /* Merging the solution from ESCAPED needlessly increases
-            the set.  Use ESCAPED as representative instead.  */
-         else if (t == find (escaped_id))
-           flag |= bitmap_set_bit (sol, escaped_id);
-         else if (v->may_have_pointers
-                  && add_graph_edge (graph, lhs, t))
-           flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
+         flag |= solve_add_graph_edge (graph, lhs, t);
 
          if (v->is_full_var
              || v->next == 0)
-- 
2.35.3